title: Superconductivity in the Anderson lattice: a finite-U slave boson description.
abstract: Using the Kotliar and Ruckenstein slave boson formalism we consider the finite-U Anderson lattice. We study the appearance of superconductivity as a function of the Coulomb repulsion, density and f-level location for s-wave and d-wave pairing symmetries. The results extend previous studies where the infinite-U limit was considered, confirming that superconductivity remains as the Coulomb coupling increases, if the attractive interaction is not weak. Superconductivity disappears for large U as the filling of the heavy particles approaches one, as expected. Since U is finite, superconductivity occurs, in general, for any band-filling being depressed near half-filling, particularly for d-wave symmetry.
authors.affiliation: Centro de Física das Interacções Fundamentais, Instituto Superior Técnico, Universidade Técnica de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal.
authors.forename: P D
authors.initials: PD
authors.lastname: Sacramento
authors.forename: J
authors.initials: J
authors.lastname: Aparício
authors.forename: G S
authors.initials: GS
authors.lastname: Nunes